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.TH "ACCESS_OK" "9" "06 August 2003" "" ""

.SH NAME
access_ok \- Checks if a user space pointer is valid
.SH SYNOPSIS
.sp
\fB
.sp
access_ok  ( \fItype\fB,  \fIaddr\fB,  \fIsize\fB);
\fR
.SH "ARGUMENTS"
.TP
\fB\fItype\fB\fR
Type of access: VERIFY_READ or VERIFY_WRITE.  Note that
VERIFY_WRITE is a superset of VERIFY_READ - if it is safe
to write to a block, it is always safe to read from it.
.TP
\fB\fIaddr\fB\fR
User space pointer to start of block to check
.TP
\fB\fIsize\fB\fR
Size of block to check
.SH "CONTEXT"
.PP
User context only.  This function may sleep.
.SH "DESCRIPTION"
.PP
Checks if a pointer to a block of memory in user space is valid.
.PP
Returns true (nonzero) if the memory block may be valid, false (zero)
if it is definitely invalid.
.PP
Note that, depending on architecture, this function probably just
checks that the pointer is in the user space range - after calling
this function, memory access functions may still return -EFAULT.
.SH "ABOUT THIS DOCUMENT"
.PP
This documentation was generated with kernel version 2.6.0.